JP7113181B2 - washing machine - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a washing machine that detects the amount of laundry in a drum and controls its stroke.

Conventionally, in this type of washing machine, a washing machine has been proposed that rotates the washing tub containing the laundry at a certain number of rotations and then detects the amount of laundry in a predetermined interval to control the process ( For example, see Patent Document 1).

FIG. 7 is a vertical cross-sectional view of a conventional drum-type washing machine disclosed in Patent Document 1, and FIG. 8 is a diagram showing the operation of the drum-type washing machine for detecting the amount of laundry.

In FIG. 7, inside the washing machine body 1, a water tub 2 is oscillatably and vibration-proof supported by a suspension structure (not shown).

A clothes entrance 4 leading to the open end of the drum 3 is formed on the front side of the water tank 2. By opening and closing the door 5 that opens and closes the opening provided on the upward inclined surface on the front side of the washing machine main body 1, the clothes can be opened and closed. , the laundry can be taken in and out of the drum 3 through the clothes entrance 4. - 特許庁

The drum 3 is formed with a large number of through holes 6 communicating with the water tank 2 on its peripheral surface, and agitation projections (not shown) for agitating clothes are provided at a plurality of positions on its inner peripheral surface. The drum 3 is rotated in forward and reverse directions by a motor 7 attached to the back side of the water tank 2 .

In addition, a water supply line 8 and a water discharge line 9 are connected to the water tank 2, and water is supplied to and drained from the water tank 2 by controlling a water supply valve and a water discharge valve (not shown).

When the door 5 is opened, the laundry and detergent are put into the drum 3, and the operation is started by operating the operation panel 10 provided on the front upper part of the washing machine main body 1, the water injection pipe line is in the water tank 2. A predetermined amount of water is injected from 8, the drum 3 is driven to rotate by the motor 7, and the washing process is started.

As the drum 3 rotates, the laundry accommodated in the drum 3 is lifted in the direction of rotation by the stirring projections provided on the inner peripheral wall of the drum 3, and the stirring operation of falling from the lifted appropriate height position is repeated. Therefore, the laundry is washed with the action of pounding.

After the required washing time, the dirty washing liquid is discharged from the drain pipe 9, and the washing liquid contained in the laundry is dehydrated by the dehydrating operation of rotating the drum 3 at high speed. Water is poured from 8 to perform a rinsing process.

Also in this rinsing step, the laundry stored in the drum 3 is rinsed by repeating the agitation operation in which the laundry is lifted by the agitation projections and dropped by the rotation of the drum 3 .

Further, a rotational speed detection unit 14 for detecting the rotation state of the motor 7 is provided on the rear surface of the motor 7. By detecting the rotational speed of the motor 7, the cloth amount detection control and the rotational speed control of the drum 3 are performed. are doing

Furthermore, a control device 15 having a control section (not shown) for controlling the operation of the drum-type washing machine is provided on the inner surface of the front lower portion of the washing machine main body 1 .

In addition, this drum-type washing machine is provided with a function of drying the laundry accommodated in the drum 3, and the air in the water tank 2 is exhausted through the circulation blowing path 11 to dehumidify it, and the laundry is dried by heating. Air is blown into the water tank 2 again. A dehumidifying means such as an evaporator, a heating means such as a condenser, and a blower fan 12 as a blowing means are provided in the middle of the air circulation path 11 . In the drying process using the circulating air passage 11, the air circulated through the circulating air passage 11 is mixed with foreign matter such as lint generated mainly from laundry such as clothes, and circulates. Clogging, getting caught in the rotating part of the blower fan 12, and depositing on the inner surface of the blower fan 12 are likely to hinder the execution of the drying process. A filter 13 is provided to remove the

In FIG. 8, the horizontal axis is the elapsed time from the start of the laundry amount detection, and the vertical axis is the rotational speed of the drum 3. When the laundry amount detection is started, the controller 15 drives the motor 7 to reach a predetermined rotational speed. From N1, the rotation speed of the drum 3 is increased by a predetermined acceleration torque T1, and controlled so that the rotation speed reaches a predetermined rotation speed N2, which is increased by ΔN1. When the drum 3 reaches N2, the required time t1 required for the rotation speed to increase by ΔN1 is calculated. This is the first detection step.

Next, after reaching a predetermined rotation speed Nmax, the rotation speed of the motor 7 is started to drop. A deceleration torque T2 is generated by the motor 7, and when the drum 3 reaches a predetermined rotation speed N4, which is a rotation speed decreased by ΔN2 from the predetermined rotation speed N3, the required time required for the rotation speed to decrease by ΔN2 is calculated. Calculate the time t2. This is the second detection step.

From these ΔN1, t1, ΔN2, and t2, the angular acceleration α1 in the first detection process and the angular acceleration α2 in the second detection process are calculated, and from the relationship between the measured value and the amount of cloth measured in advance, the cloth ask for quantity. In this cloth amount detection method, the acceleration torque T1 and the deceleration torque T2 of the motor 7 are controlled so as to be constant.

JP 2009-005722 A

However, in the conventional configuration, since the acceleration torque T1 and the deceleration torque T2 of the motor 7 are constant, the smaller the amount of cloth, the shorter the time required for N1 to N2, and the greater the angular acceleration during acceleration of the drum. Become. Conversely, when the amount of cloth increases, the time from N1 to N2 becomes longer, and the angular acceleration during acceleration becomes smaller. For this reason, it is possible to detect the amount of cloth with a certain degree of accuracy within a certain range, for example, up to about half the rated amount of cloth. In addition, the moment of inertia of the rotating system including the cloth fluctuates depending on the softness and stiffness of the clothes in the drum. There was a problem of becoming

SUMMARY OF THE INVENTION It is an object of the present invention to provide a drum-type washing machine capable of suppressing variation in the amount of laundry and detecting the amount of laundry with high accuracy.

In order to solve the above-described conventional problems, a drum-type washing machine of the present invention comprises a drum for storing laundry, and a water tank rotatably enclosing the drum and elastically supported in a washing machine body for swinging motion. a motor for rotationally driving the drum; a rotation speed detection unit for detecting the rotation speed of the connected drum by detecting the rotation speed of the motor; and a motor current detection means for detecting the current supplied to the motor. and a motor temperature detection means for detecting the winding temperature of the motor, and a control unit for controlling the motor and the like to detect the amount of laundry and controlling each process such as washing, rinsing, dehydration, etc. In the cloth amount detection process, the rotation of the drum is increased from a stationary state to a predetermined number of revolutions N1 in the low-speed rotation process, and then stepwise at the same predetermined angular acceleration during acceleration in a plurality of calculation processes. At the same time, the motor current detection means detects the motor current value during acceleration in the calculation step, and the detected motor current value at the time of acceleration and the time at the previous acceleration. When the difference from the motor current value is equal to or greater than a predetermined value, the motor is rotated from N6 to N7 at a predetermined angular acceleration during deceleration after performing the first detection step of accelerating from N4 to N5. A second detection step is performed to decrease the cloth amount, and the amount of laundry is detected by the motor current values in the first detection step and the second detection step, and the motor current value during acceleration detected in the detection step, When the difference between the motor current values detected in the previous calculation process is smaller than a predetermined value, the cloth amount detection result is corrected and the cloth amount is determined.

As a result, the amount of cloth can be detected with high accuracy by suppressing variations in cloth amount detection due to the softness and stiffness of the clothes.

The drum-type washing machine of the present invention can suppress variations in the amount of laundry to be detected depending on the softness and stiffness of the clothes, and can detect the amount of laundry with high accuracy.

FIG. 1 is a vertical cross-sectional view of a drum-type washing machine according to an embodiment of the present invention; Block circuit diagram of the control device of the drum-type washing machine Flowchart of the laundry amount detection process of the drum-type washing machine Graph diagram showing the operation of the laundry amount detection process of the drum type washing machine Vector control block diagram for detecting the amount of laundry in the drum-type washing machine A diagram showing the relationship between the drum angular velocity and the amount of change in the current value in detecting the amount of laundry in the drum-type washing machine. Longitudinal cross-sectional view of a conventional drum-type washing machine Graph diagram showing the operation of detecting the amount of laundry in the drum-type washing machine

A first invention comprises a drum for storing laundry, a water tank rotatably enclosing the drum and elastically supported in a washing machine main body, a motor for rotationally driving the drum, and the motor. a rotation speed detection unit for detecting the rotation speed of the drum connected by detecting the rotation speed of the drum, a motor current detection means for detecting the current supplied to the motor, and a motor temperature for detecting the winding temperature of the motor and a control unit for controlling each process of washing, rinsing, dehydration, etc. by controlling the motor or the like to detect the amount of laundry. to increase the rotation of the drum from a stationary state to a predetermined number of rotations N1, and then stepwise accelerate at the same predetermined angular acceleration during acceleration in a plurality of calculation steps to increase the number of rotations to N3 and N4. At the same time, the motor current detection means detects the motor current value during acceleration in the calculating step, and when the difference between the detected motor current value during acceleration and the previous motor current value during acceleration becomes a predetermined value or more, After performing the first detection step of accelerating from the number of rotations N4 to N5, the second detection step of decreasing the rotation of the motor from the number of rotations N6 to N7 at a predetermined deceleration angular acceleration is performed, and the first detection step is performed. The cloth amount is detected by the motor current values in the detection process and the second detection process, and the difference between the motor current value during acceleration detected in the detection process and the motor current value detected in the previous calculation process. is smaller than a predetermined value, the cloth amount detection result is corrected and the cloth amount is determined, thereby suppressing variation in cloth amount detection due to the softness and stiffness of the clothes, and achieving high accuracy. The amount of cloth can be detected.

In the second invention, in particular, the control unit of the first invention, in the laundry amount detection process, when the calculation process for detecting the motor current value during acceleration is less than a predetermined number of times, the acceleration detected in the detection process When the difference between the motor current value and the motor current value detected in the previous calculation process is smaller than a predetermined value, the calculation process is repeated until the calculation process reaches a predetermined number of times, thereby detecting the amount of laundry. It is possible to suppress variation and detect the amount of cloth with high accuracy.

In a third invention, in particular, the control unit of the first or second invention detects in the detection step when the calculation step for detecting the motor current value during acceleration is a predetermined number of times or more in the laundry amount detection step. The inclination is calculated from the motor current value during all accelerations, and based on the calculated inclination, the laundry amount detection result is corrected and the laundry amount is determined. The amount of cloth can be detected with accuracy.

In a fourth invention, in particular, the control unit of any one of the first to third inventions, in the cloth amount detection process, rotates the drum at a predetermined constant number of revolutions before each calculation process of a plurality of calculation processes. By providing a constant rotation step in which the clothes are rotated at , it is possible to suppress variations in the amount of cloth to be detected due to the softness and stiffness of the clothes, and to detect the amount of cloth with high accuracy.

Hereinafter, embodiments of the invention will be described with reference to the drawings. The same reference numerals are assigned to the same components as those of the conventional example, and the description thereof is omitted. Also, the present invention is not limited by this embodiment.

(Embodiment 1)
FIG. 1 is a sectional view of a drum-type washing machine according to an embodiment of the present invention, and FIG. 2 is a block circuit diagram of the drum-type washing machine.

In FIG. 1, a controller 65 having a controller 31 (see FIG. 2) for controlling a series of operations is provided inside the front surface of the washing machine main body 1. As shown in FIG.

In FIG. 2, the control device 65 rectifies the AC power of the commercial power source 20 with the rectifier 21, smoothes the DC power with the smoothing circuit consisting of the choke coil 22 and the smoothing capacitor 23, and uses the inverter circuit 24 to drive the motor. 7 is rotationally driven.

In addition, the rotation of the motor 7 is controlled based on the operation instruction input from the input setting unit 25 and the monitoring information of the operating state detected by each detection means, and the load drive unit 26 controls the water supply valve 27 and the drain valve 28 , blower fan 12 and heater 29 are controlled.

The motor 7 includes a stator having three-phase windings 7a, 7b, and 7c, a rotor having two-pole permanent magnets, and is configured as a DC brushless motor provided with three position detection elements 30a, 30b, and 30c, The rotation is controlled by an inverter circuit 24 by PWM control, which is composed of switching elements 24a to 24f.

Rotor position detection signals detected by the position detection elements 30a, 30b, and 30c are input to a control section 31 configured by a microcomputer. Based on this rotor position detection signal, the drive circuit 32 PWM-controls the on/off states of the switching elements 24a to 24f, thereby controlling the energization of the three-phase windings 7a, 7b, and 7c of the stator to rotate the rotor as required. Rotate at rpm.

The control unit 31 has a rotational speed detection unit 14 to which detection outputs of the three position detection elements 30a, 30b, and 30c are input. The rotation speed detection unit 14 detects the cycle each time the state of the signal of one of the three position detection elements 30a, 30b, and 30c changes, and calculates the rotation speed of the rotor from the cycle. The detection output of the rotation speed detection unit 14 is supplied to the cloth amount detection unit 34, and is used for cloth amount detection and rotation speed control of the drum 3 based on the detected rotation speed.

Since the detection output of the rotation speed detection unit 14 corresponds to the rotation speed of the drum 3, the rotation speed of the drum 3 is obtained from the detection output of the rotation speed detection unit 14 in the following description.

The motor current detection means 35 detects the current supplied to the motor 7 , and the motor temperature detection means 36 detects the winding temperature of the motor 7 .

FIG. 3 is a flowchart of the laundry amount detection process of the drum type washing machine according to the embodiment of the present invention, FIG. 4 is a graph showing the operation of the laundry amount detection process of the drum washing machine, and FIG. FIG. 6 is a vector control block diagram in detecting the amount of laundry in a drum-type washing machine, and FIG.

3 and 4, the horizontal axis in FIG. 4 is the elapsed time from the start of detection of the amount of laundry, and the vertical axis is the rotation speed of the drum 3. In FIG.

When clothes are put on the drum 3 and an instruction to start the washing operation is input by the input setting unit 25, the laundry amount detection process starts (step S1). The motor temperature is detected by the temperature detecting means 36, and a temperature correction coefficient is calculated (step S2).

Next, the control unit 31 slowly rotates the motor 7 for a predetermined period of time to perform the low speed rotation process of the drum 3 (step S3). In the low-speed rotation process, the motor 7 is caused to generate acceleration torque to start the drum 3 from a stationary state and accelerate it to a predetermined rotation speed N1 (eg, 60 rpm).

Here, by performing the low-speed rotation process of the drum 3, the clothes are evenly attached to the drum 3, and the moment of inertia J of the rotation system of the drum 3 including the cloth and the motor 7 is stabilized. can be started smoothly, and the amount of cloth can be detected with high accuracy.

Then, if it is determined that the predetermined time has passed (Yes in step S4), a first calculation step is performed in which the number of rotations of the drum 3 is increased by a predetermined constant acceleration α1 and controlled so that the number of rotations reaches from N1 to N2. (step S5).

If it is determined that the drum 3 has reached the number of rotations N2 (Yes in step S6), the number of calculations of the current value during acceleration is set to n=1 (step S7), and the motor current detecting means 35 detects the current during one rotation of the drum 3. A current value Iq(n) is calculated (step S8), and the first calculation step ends.

Next, in step S9, it is determined whether or not the number n of calculations of the current value during acceleration is less than a predetermined number of times. (step S10).
If it is determined that the predetermined time has elapsed (Yes in step S11), the constant rotation process is completed and the process proceeds to the second calculation process. It is controlled so that it reaches (step S12). Vector control is used for the control to accelerate the rotation of the drum 3 at the constant acceleration α1 and the control to keep the rotation of the drum 3 constant.

If it is determined that the drum 3 has reached the number of revolutions N3 (Yes in step S13), the number n of calculations of the acceleration current value is incremented by 1 (step S14), and the motor current detecting means 35 The current value Iq(n) is calculated (step S15), and the second calculation step ends.

Next, the difference (Iq(n)-Iq(n-1)) between the calculated current value during acceleration and the previous calculated value is calculated, and it is determined whether or not the difference is greater than a predetermined value (step S16).

If it is smaller than the predetermined value (No in step S16), the process returns to step S9, and the process is repeated until the calculated difference in the acceleration current value becomes larger than the predetermined value.

By performing the constant rotation process of the drum 3 before each calculation process after the second calculation process, clothes are stuck in the drum 3, so that the difference between the calculated value of the current value during acceleration and the previous calculated value becomes large, the state of softness and stiffness of the clothes can be estimated with high accuracy. A method for detecting the softness and stiffness of clothing will be described in detail with reference to FIG. 5 and subsequent figures.

The cloth amount detection process consists of a first detection process during acceleration and a second detection process during deceleration. , vector control is performed so that the rotation of the drum 3 is accelerated, and the detection process at the time of acceleration is performed from the number of rotations N4 to N5.

Vibration of the tub 2 can be reduced by avoiding the vicinity of the resonance rotation speed of the washing machine main body in consideration of overshoot and the like for the rotation speeds N4 and N5. At this time, the current supplied to the motor 7 is detected by the motor current detection means 35, and the average value or integrated value of the current values in the integral multiple rotation interval of at least one rotation of the drum 3 in the detection interval during acceleration is calculated. It is calculated as the cloth amount judgment value.

By using the average value or integrated value of the current values during one rotation (360° rotation) of the drum 3 in this manner, it is possible to cancel up-and-down fluctuations in the current value due to the biased state of clothes and the like.

Therefore, by using the current value of the integral multiple rotation section of at least one rotation of the drum 3 as the cloth amount judgment value, the up and down fluctuation of the current value due to the biased state of the clothes, etc., is offset, and the variation of the cloth amount judgment value is reduced. can be suppressed.

In step S16, when the value exceeds the predetermined value (Yes in step S16), the rotation speed of the motor 7 is started to decrease at a predetermined constant acceleration α2 (step S17), and the rotation speed is reduced from N6 to N7 during deceleration. A second sensing step of is performed.

If it is determined that the drum 3 has reached the predetermined number of rotations N6 to N7 (Yes in step S18), the current value Iq(n+1) during one rotation of the drum 3 is calculated (step S19).

As with the rotational speeds N4 and N5, the rotational speeds N6 and N7 can reduce the vibration of the tub 2 by avoiding the vicinity of the resonance rotational speed of the washing machine main body.

The motor current value Iq(n) in the first detection process when the drum 3 is accelerated from N4 to N5, and the motor current in the second detection process when the drum 3 is decelerated from N6 to N7. The amount of cloth is detected from the value Iq(n+1) (step S20).

At this time, the motor current detection means 35 detects the current supplied to the motor 7, and in the detection section during deceleration, the average value or integrated value of the current values in the integral multiple rotation section of at least one rotation of the drum is calculated. calculate. Then, the amount of laundry can be detected based on the calculated difference between the current values in the first and second detection processes.

Next, motor induced voltage correction (step S21) and temperature correction (step S22) are performed.

The motor induced voltage correction (step S21) corrects the induced voltage inherent to the motor 7 and fluctuations in the interlinking magnetic flux ψa (see FIG. 5) due to the external temperature, and utilizes the no-load state inside the drum during product assembly. Then, the magnitude of the induced voltage peculiar to the motor is detected, and correction is performed according to the magnitude of the induced voltage.

Further, in the temperature correction (step S22), the temperature of the three-phase windings 7a, 7b, and 7c adjacent to the rotor magnet is detected by the motor temperature detection means 36 to substantially detect the temperature of the rotor magnet. , temperature correction is performed accordingly.

Since motor induced voltage correction and temperature correction are conventional techniques, detailed descriptions thereof will be omitted.

Finally, based on the cloth amount detection result and the above correction, the cloth amount is finally determined based on the relationship between the cloth amount and the determination value S that has been measured in advance and stored in the cloth amount detection unit 34 (step S23). The detection ends (step S24).

In step S9, when the predetermined number of times n is reached (No in step S9), the slope of the calculated value for n times is calculated, and it is determined whether or not it is larger than a predetermined value (step S25).

When the slope of the calculated value for n times is larger than the predetermined value (Yes in step S25), the rotation speed of the motor 7 is started to decrease at a predetermined constant acceleration α2 (step S26), and the drum 3 is moved to the predetermined value. If it is determined that the number of revolutions has reached N7 from N6 (Yes in step S27), the current value Iq(n+1) during one rotation of the drum 3 is calculated (step S28).

The motor current value Iq(n) in the first detection process when the drum 3 is accelerated from N4 to N5, and the motor current in the second detection process when the drum 3 is decelerated from N6 to N7. The cloth amount is detected from the value Iq(n+1) (step S29).

Then, the cloth amount is corrected with respect to the softness and stiffness of the clothes (step S30).

On the other hand, in step S25, when the slope of the calculated value for n times (see FIG. 6) is smaller than the predetermined value (No in step S25), the process proceeds to step S17, and the motor 7 rotates at a predetermined constant acceleration α2. If it is determined that the drum 3 has reached the predetermined number of rotations N6 to N7 (step S18), the current value Iq(n+1) during one rotation of the drum 3 is calculated (step S19). , the amount of cloth is detected (step S20), and the amount of cloth is not corrected with respect to the softness and stiffness of the clothes.

After step S30, motor induced voltage correction (step S31) and temperature correction (step S32) are performed.

Finally, based on the cloth amount detection result and the above correction, the cloth amount is finally determined based on the relationship between the cloth amount and the determination value S that has been measured in advance and stored in the cloth amount detection unit 34 (step S33). The detection ends (step S28).

As described above, vector control, which is a high-performance variable speed control method, is performed in order to control the angular acceleration of the motor to be constant.

In FIG. 5, at least two-phase currents among the currents supplied to the motor 7 and a rotation position signal of the motor 7 obtained by a Hall IC or the like are detected. Using these signals, the current of the motor 7 is converted into two orthogonal currents, Iq as a torque component and Id as a magnetic flux component.

Thereafter, after comparing the converted Iq and Id with the commanded Iq* and Id*, Iq and Id of the motor 7 can be controlled by using appropriate control gains P and I. .

First, the operation state of the cloth amount detection process will be described from the mathematical aspect.

If m is the weight of the cloth, r is the average radius of the cloth distributed on the inner circumference of the drum 3, and Jd is the moment of inertia of the drum 3 and the motor 7, the moment of inertia J of the rotating system including the cloth can be obtained by Equation 1. .

In addition, the torque motion equation of the rotating system during acceleration of the drum 3 is expressed as Equation 2, where Tb is the friction torque of the drum and the rotating shaft, and J is the moment of inertia of the rotating system including the cloth. .

Similarly, the torque motion equation of the rotation system when the drum 3 is decelerated is expressed as Equation 3.

Eliminating the component of friction torque Tb from Equations 1 to 3, Equation 4 is obtained.

From Equation 4, when the average radius r of the cloth on the inner circumference of the drum, the first angular acceleration during acceleration, and the second angular acceleration during deceleration are constant values, the difference between the acceleration torque T1 and the deceleration torque T2 is the friction torque It can be seen that it does not depend on Tb and is proportional to the weight m of the cloth.

Since the torque T of the motor 7 is expressed by Equation 5, the torque T of the motor 7 can be controlled by controlling Iq and Id.

In addition, P is the number of pole pairs of the motor 7, ψa is the magnetic flux linkage by the magnet, Ld is the d-axis inductance, and Lq is the q-axis inductance. In particular, ψa·Iq in Expression 5 represents the magnet torque, which is the main component of the torque generated by the motor.

Therefore, the torque of the motor 7 can be mainly controlled by Iq. When Id is not zero, if Ld and Lq change depending on the rotation state, fluctuations in torque T or errors in calculating torque T when calculating the amount of laundry are likely to occur.

In other words, even if Iq and Id are controlled to be constant, there are cases where the torque T is not constant. By controlling, it is possible to reduce the calculation error of the amount of cloth.

From Equations 4 and 6, the relationship between the motor torque current value and the laundry amount can be expressed as Equation 7.

When the average radius r of the cloth on the inner circumference of the drum is constant, the current value changes according to the amount of cloth, that is, the weight m of the cloth.

Therefore, by grasping only the relationship between the weight of the cloth and the change in the current value and storing it as a calculation table in the cloth amount detection unit 34 shown in FIG. 2, the amount of cloth can be detected easily and accurately. .

Next, when the number of calculations of the current value during acceleration is n (n≧2), from the difference between the calculated value Iq(n) of the current value during acceleration and the previous calculated value Iq(n−1), the A method for detecting softness and stiffness will be described below. However, the weight m of the cloth is assumed to be a constant value.

If r1 is the average radius of the cloth on the inner circumference of the drum when the cloth is soft or less stiff, the moment of inertia J of the rotating system including the cloth can be obtained by Equation (8).

Similarly, if the average radius of cloth on the inner periphery of the drum when the clothes are stiff or stiff is r2, it is expressed as in Equation (9).

Also, the centrifugal force F applied to the clothes is represented by Equation (10).

From Equation 10, regarding the relationship between the average radii r1 and r2 of the cloth on the inner circumference of the drum, it is considered that hard clothes repel centrifugal force more strongly than soft clothes, so Equation 11 is obtained. Also, since the apparent volume is larger when the clothes are stiffer than when the clothes are stiffer than when the clothes are stiff, Equation 11 is similarly obtained.

In Equation 8, when the difference between the (n−1)-th time and the n-th time is taken, the acceleration-time angular acceleration α1 is a constant value.

Similarly, in Equation 9, Equation 13 is obtained by taking the difference between the (n−1)-th calculated value and the n-th calculated value.

Comparing Equation 12 and Equation 13, Equation 14 is obtained.

From Equations 6 and 14, the relationship between the motor torque current value and the average radii r1 and r2 of the cloth on the inner circumference of the drum can be expressed as Equation 15.

This indicates that the fluctuation amount of the current value is larger when the clothing is soft or less stiff than when the clothing is hard or strongly stiff.

The average radius r of the cloth on the inner circumference of the drum 3 changes according to the centrifugal force F when the drum 3 rotates, that is, the angular velocity ω.

Therefore, by grasping the relationship between the amount of change in the current value when the angular velocity ω is changed, it is possible to estimate the state of the softness and stiffness of the clothes. By correcting the amount of cloth to the heavier side in accordance with the amount of variation, variation in the amount of cloth determination value can be suppressed, and the amount of cloth can be detected with high accuracy.

In FIG. 6, from the relationship between the drum angular velocity and the amount of variation in the current value when the amount of cloth is constant, the above equation (15) can be easily understood. shown to grow.

As the drum angular velocity increases, the amount of change in the motor current value (Iq(n)-Iq(n-1)) increases as the clothing becomes softer and less stiff.

The softer and stiffer the clothing, the smaller the fluctuation amount of the motor current value even if the drum angular velocity increases.

In other words, since the motor current value changes depending on the softness and stiffness of the clothes, by accurately estimating the softness and stiffness of the clothes, the cloth amount determination value can be obtained with high accuracy as described above with reference to FIGS. can be corrected.

As described above, in the present embodiment, in the laundry amount detection process, the rotation of the drum 3 is increased from the stationary state to the predetermined number of revolutions N1 in the low speed rotation process, and then the predetermined number of rotations is obtained in the calculation process a plurality of times. At the same angular acceleration during acceleration, the rotation speed is increased stepwise to N3 and N4, and at the same time, the motor current value is detected by the motor current detection means 35 during acceleration in the calculation step, and the detected acceleration is detected. When the difference between the motor current value during acceleration and the previous motor current value during acceleration becomes a predetermined value or more, after performing the first detection step of accelerating from the rotation speed N4 to N5, the motor 7 is subjected to a predetermined angular acceleration during deceleration. A second detection step is performed to reduce the rotation speed from N6 to N7, and the amount of cloth is detected by the motor current values in the first detection step and the second detection step, and in the detection step When the difference between the detected motor current value during acceleration and the motor current value detected in the previous calculation process is smaller than a predetermined value, the cloth amount detection result is corrected and the cloth amount is determined. Therefore, it is possible to detect the amount of cloth with high accuracy by suppressing variations in cloth amount detection due to the softness and stiffness of the clothes.

Further, in the cloth amount detection process, when the calculation process for detecting the motor current value during acceleration is performed a predetermined number of times or less, the motor current value during acceleration detected in the detection process and the motor current detected in the previous calculation process are combined. When the difference between the values is smaller than a predetermined value, the calculation process is repeated until the calculation process reaches a predetermined number of times, thereby suppressing variations in the amount of cloth to be detected and detecting the amount of cloth with high accuracy. can be done.

In addition, in the cloth amount detection process, when the calculation process for detecting the motor current value during acceleration is performed a predetermined number of times or more, the slope is calculated from all the motor current values during acceleration detected in the detection process, and the calculated slope is obtained. Based on this, by correcting the laundry amount detection result and determining the laundry amount, variations in the laundry amount detection can be suppressed, and the laundry amount can be detected with high accuracy.

In addition, in the cloth amount detection process, a constant rotation process of rotating the drum 3 at a predetermined constant number of revolutions is provided before each calculation process of a plurality of times of calculation processes. The amount of cloth can be detected with high accuracy by suppressing the variation in the amount of cloth detected due to the state of .

As described above, the washing machine according to the present invention can accurately detect the amount of cloth loaded into the drum with a simple configuration and perform process control. It can be applied to the use of

REFERENCE SIGNS LIST 1 washing machine body 2 water tank 3 drum 7 motor 14 rotation speed detection unit 31 control unit 35 motor current detection means 36 motor temperature detection means

Claims (6)

A drum that accommodates laundry and rotates, a water tank that contains the drum and is elastically supported in a washing machine body, a fluid balancer that is positioned in the water tank and is provided on the drum, and the drum. A motor that rotates, a current detection means that detects a current supplied to the motor, and a control unit that controls rotation of the motor, the control unit causing the motor to generate an acceleration torque to generate the acceleration torque. a first detection step of accelerating the rotation of the drum, controlling the motor torque so that the angular acceleration of the drum during the first acceleration is constant, and detecting the current value during acceleration supplied to the motor; After the first detection step, the rotation of the drum is decelerated by causing the motor to generate a deceleration torque so that the second deceleration angular acceleration of the drum is constant in a predetermined deceleration section. a second detection step of controlling the motor torque and detecting a current value during deceleration supplied to the motor, and calculating a cloth amount determination value based on the current value during acceleration and the current value during deceleration. and calculating the current value during acceleration at least twice in a predetermined acceleration interval in which the rotational speed of the drum is different and the same as the first angular acceleration during acceleration, and the cloth amount determination value is calculated. Afterwards, the washing machine has laundry amount detection means for determining the laundry amount by correcting the laundry amount judgment value based on the difference between the calculated current value during acceleration and the previous calculated value. When the number of calculations of the current value during acceleration is at least two times, the cloth amount detection means detects a second 2. The washing machine according to claim 1, wherein the current value during acceleration is repeatedly calculated until a predetermined number of times is reached in a predetermined acceleration interval in which the angular acceleration is the same as that of 1 and the number of revolutions of the drum is different. When the number of calculations of the current value during acceleration is at least two or more, the cloth amount detection means calculates a slope from all the current values during acceleration calculated in the acceleration section, and based on the calculated slope, detects the amount of cloth. 3. The washing machine according to claim 1, wherein the judgment value is corrected. When the number of calculations of the acceleration current value is three, the cloth amount detection means detects the difference between the first calculated value and the second calculated value, and the difference between the second calculated value and the third calculated value. 4. The washing machine according to any one of claims 1 to 3, wherein the laundry amount determination value is corrected based on the slope calculated from all the calculated acceleration current values. 5. The washing machine according to any one of claims 1 to 4, wherein the laundry amount detection means calculates the current value in an integral multiple rotation interval of at least one revolution of the drum in the acceleration interval. . When the number of calculations of the current value during acceleration is at least two or more, the cloth amount detection means detects a constant rotation section of the drum to which the clothes are more attached for a predetermined time before the second and subsequent calculation steps. The washing machine according to any one of claims 1 to 5, further comprising:

Images